A combined analysis ("meta-analysis") of eight case-control studies demonstrated a statistically significant association between exposure to radon in the home and lung cancer risk. The risk level found was consistent with risks estimated by extrapolation from studies of underground miners, who are exposed to higher radon levels. Related work confirmed that for equal total exposure to radon, a low exposure rate for a long duration imparts greater risk than a high exposure rate for a short duration. This "inverse exposure-rate" effect is diminished, however, at low total exposures, such as are found in the home. A study of lung cancer and indoor radon is underway in China in an area where many homes have a high radon concentration. Heavy alcohol consumption was associated with a doubling of risk of prostate cancer, in U.S. blacks and whites, and, in a separate study, with a doubling of the risk of pancreatic cancer in U.S. blacks and whites. No association was found between pancreatic cancer and low doses of alcohol consumption in Shanghai, China, however. Exposure to nitrates in drinking water was associated with increased risk of non-Hodgkin's lymphoma in one case-control study, and exposure to chlorination products in water was associated with increased risk of rectal cancer, but not colon cancer, in one study and with increased risk of bladder cancer in a second study, but only among smokers. Certain heterocyclic aromatic amines (HAAs) are carcinogenic in rodents. Pan-fried, oven-broiled, and grilled chicken were found to contain high levels of HAAs in one study. In another study, high levels of endogenous cytochrome P4501A2 were associated with lower levels of one type of HAA in subjects fed lean ground beef. We developed conversion factors from measurements of HAA levels in foods to permit estimation of HAA intake from dietary questionnaires. Subjects who used anorexic drugs such as fenfluramine for more than 3 months had a 23-fold increased risk of primary pulmonary hypertension, which is often fatal.